Bicycle component tube

Abstract

A bicycle subassembly includes a bicycle component having a socket and a tube having a first tube portion received in the socket and a second tube portion extending outwardly from the socket. The tube includes a cold worked region spanning at least a portion of the first tube portion and at least a first portion of the second tube portion. The tube includes a non-cold worked region spanning at least a second portion of the second tube portion. Methods for making the tube and subassembly are also provided.

What is claimed is: 
     
       1. A bicycle subassembly comprising:
 a bicycle component comprising a socket; and 
 a tube having a first tube portion received in the socket and a second tube portion extending outwardly from the socket, wherein the first and second tube portions are integrally formed of a same material, wherein the tube comprises a first region having a first material property extending over at least a portion of the first tube portion and at least a first portion of the second tube portion, and wherein the tube comprises a second region having a second material property extending over at least a second portion of the second tube portion, wherein the first and second material properties are different. 
 
     
     
       2. The bicycle subassembly of  claim 1  wherein the first material property is a first residual compressive stress at an outer surface of the tube and the second material property is a second residual compressive stress at the outer surface of the tube. 
     
     
       3. The bicycle subassembly of  claim 2  wherein the first region comprises a cold worked region and wherein the second region comprises a non-cold worked region. 
     
     
       4. The bicycle subassembly of  claim 3 , wherein the tube comprises a first tube and the non-cold worked region defines a sealing surface of the first tube, and further comprising a second tube movably engaged with the sealing surface. 
     
     
       5. The bicycle subassembly of  claim 1 , wherein the bicycle component comprises a front fork crown. 
     
     
       6. The bicycle subassembly of  claim 3 , wherein the cold worked region comprises a connection zone and a transition zone, wherein the connection zone has a uniform residual compressive stress at an outer surface of the tube, and wherein the transition zone has a gradient residual compressive stress defined along a length of the tube at the outer surface of the tube. 
     
     
       7. The bicycle subassembly of  claim 6 , wherein the gradient residual compressive stress transitions from the uniform residual stress of the connection zone to a residual stress of the non-cold worked region at an outer surface of the tube. 
     
     
       8. The bicycle subassembly of  claim 3 , wherein the cold worked region has a first roughness at an outer surface of the tube and the non-cold worked region has a second roughness at the outer surface of the tube, wherein the second roughness is different than the first roughness. 
     
     
       9. The bicycle subassembly of  claim 8 , wherein the second roughness has a first value of Ra 0.075 to 0.30 and a second value of Rz 0.75- 3.75 and the first roughness has a first value of Ra 1.475 to 4.080 a second value of Rz 7.303- 18.504. 
     
     
       10. The bicycle subassembly of  claim 3 , wherein at least a portion of the cold-worked region has a compressive residual stress of at least minus 100 MPa at an outer surface of the tube. 
     
     
       11. A front fork assembly for a bicycle comprising:
 a crown comprising a socket; and 
 a leg portion formed as a tube having an end portion received in the socket, wherein the end portion and the socket have an overlapping region defined by a first length, wherein the end portion of the tube comprises a cold worked region including the overlapping region and having a second length, wherein the second length is greater than the first length, and wherein the tube has an overall third length, wherein the third length is greater than the second length. 
 
     
     
       12. The front fork assembly of  claim 11 , wherein the tube comprises a non-cold worked region adjacent the cold worked region. 
     
     
       13. The front fork assembly of  claim 12 , wherein the tube comprises an upper tube and the non-cold worked region defines at least a portion of a sealing surface of the upper tube, and further comprising a lower tube movably engaged with the sealing surface. 
     
     
       14. The front fork assembly of  claim 11 , wherein the cold worked region comprises a connection zone and a transition zone, wherein the connection zone has a uniform residual compressive stress at an outer surface of the tube, wherein the connection zone has a fourth length greater than the first length and less than the second length, and wherein the transition zone has a gradient residual compressive stress defined along a fifth length of the tube at the outer surface of the tube. 
     
     
       15. The front fork assembly of  claim 14 , wherein the gradient residual compressive stress transitions from the uniform residual stress of the connection zone to a residual stress of the non-cold worked region at the outer surface of the tube. 
     
     
       16. The front fork assembly of  claim 15 , wherein the residual compressive stress of the non-cold worked region is approximately zero at the outer surface of the tube. 
     
     
       17. The front fork assembly of  claim 11 , wherein the second length is at least 5 mm greater than the first length. 
     
     
       18. The front fork assembly of  claim 12 , wherein the cold worked region has a first roughness at an outer surface of the tube and the non-cold worked region has a second roughness at the outer surface of the tube, wherein the first roughness is rougher than the second roughness. 
     
     
       19. The front fork assembly of  claim 18 , wherein the second roughness has a first value of Ra 0.075 to 0.30 and the first roughness has a first value of Ra 1.475 to 4.080, and, wherein the second roughness has a second value of Rz 0.75- 3.75 and the first roughness has a second value of Rz 7.303- 18.504. 
     
     
       20. The front fork assembly of  claim 11 , wherein at least a portion of the cold-worked region has a residual compressive stress of at least minus 100 MPa at an outer surface of the tube.